you can force players to take certain decisions (i dont think i played 4 terrible german players in a row):
1. By building an IC in South Africa Germany will send many troops into Africa or leave Africa for what it is. Either way is good for you. If he tries conquering africa, he has to weaken his european force, leaving Africa to the allies means lots of ipc’s less.
2. By defending Yakut with 5 or 6 infantry allmost all japanese players take southern asia early and dont concentrate on russia, meaning that russia can get up to 30 IPC income or even more.
It works against allmost all players.
Germany is weak itself, it doesnt really matter that much who plays with it. Its simply impossible to defend Eastern Europe with infantry only. Russia can crush Eastern Europe on turn 2 destroying all armor there, which usually is alot. And with the forces in Eastern Europe destroyed Germany cannot defend itself against invasions by all 3 allies. Germany will most likely fall on turn 4 or 5 then, by that time Japan has reached Moscow but Russia can afford buying enough infantry to defend it while the other allies finish off the last remains of Germany.